CrAl multilayer coatings with 5 nm Al and 35, 19, and 14 nm Cr layers were deposited on Zr-4 substrates by magnetron sputtering. The effect of Cr layer thickness on Al diffusion and oxide scale evolution during 1200 ℃ steam oxidation was investigated. Decreasing Cr thickness from 35 to 14 nm densified the columnar structure and shifted the orientation from Cr(110) to Cr(200). In the thin Cr coating, high interface density and Cr(200) texture promoted Al outward diffusion, forming a continuous external Al2O3 scale. Near-surface Al depletion then triggered competitive Cr2O3/Al2O3 growth. In the intermediate coating, sustained competitive oxide growth produced a porous mixed Cr2O3/Al2O3 scale. The poor oxygen barrier of this mixed scale allowed oxygen ingress, inducing Zr oxidation along grain boundaries and continuous ZrO2 network formation. In the thick Cr coating, outward Cr3+ diffusion formed a dense Cr2O3 scale, while Al enriched in the underlying Cr-depleted zone oxidized into an inner Al2O3 scale. These findings provide a mechanistic basis for designing CrAl multilayer coatings with optimized oxidation resistance.

The development of monolayer hole-selective contacts has proven to be an effective strategy for enhancing the performance and scalability of inverted perovskite solar cells (PSCs). However, current monolayer molecules often suffer from limited charge separation and extraction capabilities due to their small π-conjugated domains, localized carrier orbitals, and weak interfacial binding with substrates. Here, we report a molecular design featuring a double donor-acceptor (D-A) conjugated architecture with an enhanced push-pull effect, spatially separated carrier orbitals for efficient hole extraction and electron blocking, bifacial anchoring for strong binding to both metal oxide substrates and perovskite layers, and a twisted π-skeleton that suppresses self-aggregation and ensures homogeneous monolayer distribution. By replacing conventional [2-(9H-carbazol-9yl)ethyl]phosphonic acid (2PACz) with this double D-A-type monolayer, the PCE improves from 23.69% to 25.61% (certified 25.11%) in small-area PSCs, while large-area perovskite modules (active area of 10.04 cm2) achieve a high PCE of 21.40%. Notably, the devices exhibit excellent operational stability under continuous illumination (100 mW cm-2) at an elevated temperature (85 °C), maintaining 84.9% of the initial efficiency after 1000 h.

The self-assembled monolayer (SAM) has driven the rapid increase in the power conversion efficiency (PCE) of perovskite solar cells (PSCs). However, the operation stability of these PSCs under real conditions continues to be challenging. We developed an SAM based on phthalocyanine, which has a structurally robust framework with chemically stable bonds that enhance photostability. Tetraphosphorylation further enables the firmly locked phthalocyanine at the interface, which improves thermal stability, charge extraction, and assembly uniformity. Implementing this approach, a certified efficiency of 23.1% (stabilized 22.9%) for a perovskite solar module over a 20.3-square centimeter aperture area was achieved and the outdoor stability analysis was conducted following the ISOS-O-1 protocol, exhibiting no performance degradation throughout the entire outdoor aging test for 61 days, demonstrating reliable durability under real conditions.

Sputtered nickel oxide (NiOx) is an industrially compatible hole transport layer for perovskite solar cells (PSCs), yet its practical deployment is limited by interfacial instability arising from disordered Ni3+ species and unfavorable reactions with perovskite absorbers. Here, we introduce an in situ dissociative adsorption passivation (IDAP) strategy using bromoacetamide (BAA) to stabilize sputtered NiOx. In this approach, Br- ions act as site-blockers by coordinating with surface Ni, suppressing interfacial disorder and stabilizing Ni3+ species, while the amide group provides dual anchoring: N-H···O hydrogen bonding strengthens attachment to NiOx, and the carbonyl group (C═O) passivates the uncoordinated Pb2+ located at or near the interface between the NiOx and the perovskite films. These cooperative efforts reduce trap states, suppress interfacial redox reactions, and mitigate defect-driven degradation under thermal stress. PSCs incorporating BAA-NiOx achieve a champion power conversion efficiency (PCE) of 26.31% along with a certified PCE of 26.07%, while the larger-area PSCs (1 cm2) maintain 25.48% efficiency. This is one of the highest efficiencies reported for NiOx-based PSCs. In addition, the encapsulated cell retains 93% of its initial performance after 1500 h of continuous operation.

Two terminal-chlorinated ortho-benzodipyrrole (o-BDP)-based non-fullerene acceptors (NFAs), CFB-Cl and CMB-Cl, were designed and synthesized by incorporating fluorine or methyl substituents on the o-BDP core, respectively. Compared to their terminal-fluorinated counterparts, both NFAs exhibit red-shifted absorption, higher melting points, and stronger intermolecular interactions, attributed to the introduction of chlorinated end groups. Single-crystal X-ray analysis of CFB-Cl revealed a compact three-dimensional kaleidoscopic packing network stabilized by unique F···Cl halogen interactions between the fluorinated o-BDP core and the chlorinated end group, leading to a short π-π stacking distance of 3.38 Å and enhanced charge transport. Consequently, PM6:CFB-Cl devices achieved a PCE of 16.62% with a fill factor (FF) of 75.54%, outperforming PM6:CMB-Cl (PCE = 16.13%). To further improve device performance, a ternary blend strategy was employed by introducing the fluorinated CMB into PM6:CFB-Cl blends to extend the absorption range and improve the morphology. The resulting PM6:CFB-Cl:CMB inverted device exhibited excellent miscibility (χ = 0.02 K), balanced carrier transport (μe/μh = 1.38), suppressed recombination, and a highest PCE of 17.26% with Jsc = 26.02 mA cm-2 and Voc = 0.892 V. This work highlights the importance of halogen engineering in regulating molecular packing and charge dynamics, providing insights into the structure-morphology-performance relationship of o-BDP-based NFAs for next-generation organic photovoltaics.

The performance of inverted perovskite solar cells (PSCs) is often impeded by severe non-radiative recombination and carrier transport losses at the self-assembled monolayer (SAM)/perovskite interface, arising from inhomogeneous SAM distribution and weak interfacial bonding with the perovskite layer. To address these challenges, we introduce a universal synergistic interface engineering strategy employing 2-aminopyrimidine-4-carboxylic acid (m-APCA), a meta-substituted molecule featuring asymmetric bifunctional groups on its pyrimidine ring. These groups induce substantial molecular polarization, amplifying the dipole moment and reinforcing intermolecular π-π interactions with SAMs, thereby mitigating SAM aggregation and ensuring uniform substrate coverage. Concurrently, the strong dipole field and bifunctional chemistry of m-APCA enable robust chemical bonding with the perovskite layer, acting as nucleation sites that regulate grain growth and passivate buried interfacial defects. This dual-action approach reduces interfacial energy barriers and enhances hole transport efficiency, achieving very high efficiencies of 26.77% (certified at 26.71%), 26.08%, and 24.17% for small-area (normal bandgap), centimeter-scale (normal bandgap), and wide-bandgap PSCs, respectively. Notably, optimized PSCs demonstrate exceptional operational stability, retaining 96% of initial efficiency after 1200 h of continuous maximum power point tracking.

ABSTRACT Surface passivation is an effective strategy to address Sn 2+ oxidation and interfacial defects. However, current studies have primarily focused on the interaction between passivators and perovskites, while neglecting the influence of intermolecular interactions among passivators on their aggregation morphology and passivation efficacy. Herein, 6‐methylnicotinic acid hydrazide (MAH) and 6‐aminonicotinic acid hydrazide (AAH) were employed as passivators for a comparative study. Theoretically, the strong electron‐donating amino group (─NH 2 ) in AAH should endow it with stronger reducing and coordination abilities, yet the opposite phenomenon was observed in solid films, where AAH exhibited inferior passivation and antioxidant performance compared to MAH. It was found that the ─NH 2 group in AAH acted as a hydrogen‑bond donor and acceptor, inducing strong intermolecular hydrogen bonding and self‐aggregation, which led to disordered multilayer stacking on the perovskite surface and shielded the active functional groups. The methyl group with moderate steric hindrance in MAH effectively prevented self‑aggregation, allowing MAH to uniformly distribute on the perovskite surface and form bidentate coordination with Sn 2+ , thereby efficiently inhibiting Sn 2+ oxidation and passivating defects. The MAH‑treated Sn–Pb device achieved an efficiency of 23.92%, and when integrated into an all‑perovskite tandem cell, the device efficiency was further increased to 29.31%.

The past two years have witnessed remarkable progress in perovskite solar cells(PSCs),marked by breakthroughs in power con-version efficiency and strides in addressing long-term operational sta-bility.At present,the certified power conversion efficiencies of single-junction PSCs and silicon/perovskite tandem cells have surpassed 27％and 34％,respectively.Regarding stability,researchers begun to focus their attention on the challenges faced by PSCs when operated in out-door environments.Furthermore,breakthroughs in the utilization of green solvents,fabrication in ambient air conditions,aqueous-phase synthesis of perovskite raw materials at kilogram scale,vacuum flash evaporation,and machine learning-assisted design are accelerating the commercialization of PSCs.The review summarizes the key advance-ments of PSCs during 2024-2025.It identifies a critical performance discrepancy between small-area devices and perovskite solar modules and delves into strategies aimed at bridging this gap.Finally,perspectives on the future directions of PSCs are presented,with a particular emphasis on improving photocurrent and environmental sustainability.

The rapid development of self-assembled monolayers (SAMs) has been instrumental in advancing the power conversion efficiency (PCE) of inverted perovskite solar cells (PSCs) to exceed 26%. However, benchmark SAMs are limited by stochastic assembly kinetics and weak interfacial coupling with the perovskite, which induce severe interfacial recombination and compromise device stability. Here, we developed an amino acid hydrochloride (AAH)-mediated SAM to construct high-performance PSCs. By systematically modulating the AAH alkyl spacer length, we elucidate an optimal steric profile that balances thermodynamic anchoring with kinetic intermolecular organization. This optimized AAH-mediated SAM exhibits enhanced coverage, uniformity, and molecular packing density, stabilizing the interface via reduced defect density and refined energy level alignment. Moreover, the AAH terminal ammonium (-NH3 +Cl-) moieties establish a chemical bridge with the perovskite, effectively passivating interfacial defects and promoting stress-free crystallization. Consequently, the devices based on AAH-mediated SAMs delivered a champion PCE of 26.87% (certified at 26.33%) on a 0.058 cm2 area and 25.90% on a 1-cm2 area. Encapsulated device exhibited excellent operational stability, retaining over 97.3% of its initial efficiency after 1100 h of continuous operation at the maximum power point in air.

The commercialization of perovskite photovoltaics faces significant hurdles due to device degradation under environmental stressors, such as illumination, humidity and heat, which represents a core challenge for industrial applications. Here we present a conformational engineering strategy targeting the buried interface of perovskite solar cells and based on the structural evolution of additives-from 1,1-diphenylethylene to 1-octyl-2-(1-phenylvinyl)benzene and diethylamino hydroxybenzoyl hexyl benzoate. We decouple the contributions of the additives, including ultraviolet shielding, strain regulation and chemical passivation. In conjunction with in situ characterization, we reveal that dynamic interfacial strain regulation plays a major role in improving device stability during light-dark cycling. Our devices achieve power conversion efficiencies of 26.47% and 22.67%, for active areas of 0.09 cm2 and 20.5 cm2, respectively. Under maximum power point tracking, small-area devices maintain 96.2% of their initial power conversion efficiency after 1,132 h of testing in ISOS-L-1I (continuous illumination) and 88.8% after 348 h in ISOS-LC-1 (12-h day-night cycling). This research establishes an innovative design paradigm for stable and efficient perovskite solar cells through a multifunctional strategy driven by conformational engineering.

Upward unidirectional crystallization is achieved by maximizing the difference in nucleation driving force between top and bottom sides of perovskites, which contributes to efficient and stable solar cells with eliminated high-dimensional defects.

Gas-medium annealing simultaneously accomplished crystallization and surface passivation, contributing to high-quality perovskite films with much fewer defects from bulk to surface. A minimized energy loss of 0.29 eV was obtained for efficient PSCs.

Inverted perovskite solar cell has made significant progress in recent years. Although two-step sequential deposition shows the benefits to obtain higher quality large-size perovskite crystals, the high annealing temperature, which is required to achieve phase transition, leads to the desorption of self-assembled molecules at the buried interface and induces redundant lead iodide at the top interface. Here, we propose a low temperature sequential deposition method by introduce a tailor-made 3-ethyl-1-methyl-1H-imidazol-3-ium dimethyl phosphate into lead iodide precursor solution to facilitate the sufficient reaction between lead iodide and organic salts, and lower the energy barrier from delta- to alpha-perovskite. As a result, highly crystallized and pure alpha-phase perovskite films with large grain size are fabricated, preventing the damage to buried self-assembled molecules and the formation of redundant lead iodide, which contributes to a high open circuit voltage of 1.21 V and a certified efficiency of 26.0%. The encapsulated devices show improved stability following ISOS-D-3 and ISOS-L-2 protocols.

The dielectric constant (ε r) of non-fullerene acceptors is a key parameter in organic solar cells, significantly influencing exciton dissociation efficiency and charge recombination dynamics. Substituting bromine, characterized by moderate electronegativity and high polarizability, at the o-benzodipyrrole core of acceptors effectively modulates their optical properties, molecular packing, and dielectric constants. The asymmetric monobrominated CBrB-Cl acceptor exhibits a more red-shifted absorption spectrum, enhanced crystallinity, and a higher ε r of 3.92, contributing to a high efficiency of 17.69% in the inverted PM6:CBrB-Cl device. Further, a selenium-incorporated CB-Se acceptor was selected to form a well-matched dual asymmetric acceptor alloy. The combination of heavy bromine and selenium atoms in the CBrB-Cl:CB-Se alloy increase the ε r of the PM6:CBrB-Cl:CB-Se blend film to 4.23, which in turn reduces exciton binding energy, promotes efficient charge separation, and suppresses charge recombination, as evidenced by a faster charge separation time (τ rise = 0.39 ps) and a longer charge carrier lifetime (τ decay = 309 ps). The inverted PM6:CBrB-Cl:CB-Se device achieved a high PCE of 18.33%, which is considered to be one of the highest among inverted OPV devices. This work reveals that bromine/selenium substitution enhances the dielectric constant and crystalline packing, thereby advancing molecular design and improving device performance.

MoAlB, with a blend of metallic and ceramic attributes, receives special attention for high-temperature protective applications. Nevertheless, the formation of volatile oxides resulting from Al depletion accelerates the degradation of MoAlB. In this study, we adopted a configurational design strategy specifically targeting the insitu precipitation of MoAlB nanocrystals within amorphous composites to achieve an amorphous/nanocrystalline composite structure of MoAlB (ACCS-MoAlB), for enhancing its oxidation resistance and elucidating the atomic-level oxidation mechanism of MoAlB. The obtained ACCS-MoAlB sample exhibited remarkable resistance to oxidation in ambient air at 1200 degrees C. This is because the rapid formation of a protective alpha-Al2O3 scale generated by the synergistic interaction between metastable amorphous composites (resistant to oxygen permeation) and MoAlB nanocrystals (exhibiting selective oxidation behavior), as well as the slow growth characteristics of the scale due to the nucleation and growth of both these structural units exposed to thermal conditions during the oxidation process. Among them, the selective oxidation behavior of MoAlB was observed as a result of vacancy-mediated preferential outward migration of Al along the [100] direction. Furthermore, the good adhesion between the oxide scale and the Al-depleted MoAlB matrix was found to originate from the dislocation-free coherent epitaxial growth of alpha-Al2O3.

The NiOx/self-assembled monolayer (SAM) hole transport bilayer has emerged as the preferred architecture for high-performance inverted perovskite solar cells (PSCs). However, the redox reactions occurring at the NiOx/perovskite interface under photo-thermal stress induce the degradation of perovskite, which poses severe challenges to long-term stability. Here, tailored functionalized nicotinic acid derivatives are incorporated into commonly-used carbazole-based SAMs through a co-assembled strategy. They can act as redox mediators, which not only prevent detrimental interface chemical reactions by reducing Ni4+, but also trigger the elimination of both Pb0 and I0 defects that are generated during the long-term device operation. As a result, a power conversion efficiency of 26.03% is obtained, retaining 92.80% of the initial performance after 1,200 h of operation, following ISOS-L-3 protocol.

Formamidinium‐cesium lead iodide perovskites (FA 1‐x Cs x PbI 3 , 0 < x < 0.1) are promising solar cell absorber materials with favorable bandgap and high thermal stability. However, the fabrication of high‐quality FA 1‐x Cs x PbI 3 films with large grain size, stable black phase, uniform cations distribution, and minimal defects remains challenging. Here, the efficacy of cyanovinyl phosphonic acid (CPA) based molecular additives in fabricating high‐quality FA 0.95 Cs 0.05 PbI 3 films is reported. The CPA unit shows strong interactions with all species of lead iodide (PbI 2 ), formamidinium iodide (FAI), and cesium iodide (CsI) in the precursor solution, thus significantly alleviating the inhomogeneous crystallization in this mixed‐cation system. The resulting FA 0.95 Cs 0.05 PbI 3 films exhibit enlarged grain size and homogenized cation distribution, and the presence of CPA‐based molecules in final perovskite films enhances optoelectronic qualities and photostability owing to efficient passivation and strong interaction with perovskite. With optimizations on molecular size and adding concentrations, inverted structured perovskite solar cells based on an optimal molecular additive (Ph‐CPA) achieve power conversion efficiencies (PCEs) up to 26.25%. Moreover, the lifespans (T90, time corresponding to 90% of initial PCE retained) of the devices are unprecedentedly prolonged from hundreds of hours to over 1000 and 3000 h under light and thermal stresses (ISOS‐L‐2I, 85 °C) and operational condition (ISOS‐L‐1I), respectively.

The emergence of intrinsic defects during the growth of perovskite films severely constrains further advancements in the efficiency and stability of perovskite solar cells (PSCs). To address the challenge of mitigating defects in perovskite films, we incorporated 4-methylsulfonylbenzoic acid (4-MeSBA), a multifunctional additive, into the perovskite precursor solution. This additive significantly reduces defects in perovskites through a molecular locking mechanism. Specifically, the molecule's two oxygen-bearing functional groups engage in simultaneous bonding interactions with uncoordinated lead ions, formamidine species, and iodine atoms present at the grain boundaries of the perovskite. Furthermore, the synergistic effect mediated by 4-MeSBA through hydrogen bonding and coordination interactions not only facilitates more controlled crystal growth of perovskites but also enhances the overall quality of the perovskite film, thereby contributing to improved performance of PSCs. Indeed, we achieved a champion PSC with a power conversion efficiency of 26.35% measured in-house, along with a certified efficiency of 26.00%. The encapsulated 4-MeSBA-based PSC retained over 92% of its initial efficiency after 1200 hours of maximum power point tracking in air.

Pure black‐phase FAPbI 3 has always been pursued because of its ideal bandgap ( E g ) and high thermal stability. Here, a pair of sacrificial agents containing diethylamine hydrochloride (DEACl) and formamide (Fo) is reported, which can induce the oriented growth of black‐phase FAPbI 3 along (111) and will disappear by the aminolysis reaction during perovskite annealing, retaining the E g of FAPbI 3 as 1.49 eV. In addition, the tensile strain of the target FAPbI 3 is found to be mitigated with a stabilized black phase due to the tilt of FA + . The devices based on the pure and stable black‐phase (111)‐FAPbI 3 achieved a power conversion efficiency of 25.2% and 24.2% (certified 23.51%) with an aperture area of 0.09 and 1.04 cm 2 , respectively. After 1080 h of operation at the maximum power point under 1‐sun illumination (100 mW cm −2 ), the devices maintained 91.68 ± 0.72% of the initial efficiencies.